1. Field of the Invention
The present invention relates to a subject discriminating apparatus that discriminates a subject having an unevenness pattern on its surface, and a coin discriminating apparatus.
Priority is claimed on Japanese Patent Application No. 2011-076341, filed Mar. 30, 2011, the content of which is incorporated herein by reference.
2. Description of Related Art
As subject discriminating apparatuses that discriminate a subject having an unevenness pattern on its surface, coin discriminating apparatuses, which image a coin and discriminate the coin based on the acquired image data, are known. Such coin discriminating apparatuses generally carry a plurality of coins and sequentially image the surfaces of the coins that are carried to an imaging region. Coin discriminating apparatuses includes, for the imaging, a light source which irradiates an illumination light on the coin surface, and an imaging unit which receives the reflected light that is reflected from the coin surface (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2000-306135 (hereunder referred to as Patent Document 1)).
In the coin discriminating apparatus disclosed in Patent Document 1, the coin is carried while being pressed against the surface of a transparent member by a carrying belt. The transparent member is composed of a light-transmissive material such as glass. The light source is arranged on the lower side of the transparent member, performing light emission in a timing at which the coin passes through the imaging region, and irradiates the illumination light onto the coin surface via the transparent member. The imaging unit is arranged such that it is directly facing the coin surface, and receives, among the illumination light, mainly the reflected light reflected from the coin surface. The discrimination of the coin is performed by comparing the image data acquired by the imaging unit, with pre-recorded data which represents the types of coins.
However, in the coin discriminating apparatus disclosed in Patent Document 1, in addition to the reflected light from the coin surface, reflected light that is reflected at the surface of the transparent member on the side in which the coin is carried, and reflected light that is reflected at the surface of the transparent member on the side in which the illumination light is irradiated, are also incident on the imaging unit. Consequently, an accurate discrimination using the acquired image data can no longer be performed, causing a decline in the discrimination accuracy. Furthermore, the images created based on this image data are displayed such that the periphery of the coin is whitishly blurred as a result of the reflected light from the transparent member surfaces being imaged, making visual recognition more difficult.